Monday, March 2, 2020

The "Biggest Cosmic Explosion On Record" ? Yes- And It's Definitely Not Fake News

Image may contain: night and text
Time now to change focus from the COVID-19  virus, Dotard and  the Dem campaign to a natural  calamity in deep, deep space. We now know, thanks to a recent paper published in The Astrophysical Journal., that the biggest cosmic explosion on record  has been detected. This is an event so powerful that it punched a dent the size of 15 Milky Ways in the surrounding space.  The eruption is thought to have originated at a supermassive black hole in the Ophiuchus galaxy cluster, which is about 390m light years from Earth.

Lead author Simona Giacintucci, of the Naval Research Laboratory in Washington DC,  described the blast as an astronomical version of the eruption of Mount St.  Helens in 1980, which ripped off the top of the volcano.  She explained:

 “A key difference is that you could fit 15 Milky Way galaxies in a row into the crater this eruption punched into the cluster’s hot gas,”

Galaxy clusters are among the largest structures in the universe, containing thousands of individual galaxies, dark matter and hot gas. E.g.
Image result for galaxy clusters
At the heart of the Ophiuchus cluster we know there is a large galaxy that contains a supermassive black hole with a mass equivalent to 10 million suns.  That would be:

10  x  1.99 x  10 30   kg   =     19.9 x  10 30   kg    

Although black holes are known as 'sinkholes' that consume anything that drifts too close, they also expel prodigious amounts of material and energy. These jets occur when a disk of plasma accretes around the central black hole.  An artist's conception of one such jet is shown below:
Image may contain: night
When the inward flow of material reaches a certain limit, a proportion escapes being swallowed by the black hole and is redirected into plasma jets that blast out in two perpendicular beams at close to the speed of light.

In the case of the Ophiuchus object, astrophysicists conjecture a jet would have traveled in a narrow beam for a certain distance, then hit something in space, which caused the beam to explode outwards in a burst of radio emissions. Maxim Markevitch, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a co-author of the paper, compared the process to a stream of air travelling down a drinking straw and then turning into a bubble at the end of the straw.

The first hints of the giant explosion were spotted by NASA’s Chandra X-ray Observatory in 2016, which showed an unusual concave edge in the Ophiuchus galaxy cluster. However, at the time the possibility of this being caused by an explosion was discounted due to the huge amount of energy required to create such a large cavity.

The latest observations combined data from Chandra and ESA’s XMM-Newton space observatory and radio data from the Murchison Widefield Array (MWA) in Australia and the Giant Metrewave Radio Telescope (GMRT) in India to provide compelling new evidence for the gigantic explosion.

The observations confirm the presence of the curved edge and also reveal a huge patch of radio emissions tightly bordering the curve, which would correspond to the expected bubble. “This is the clincher that tells us an eruption of unprecedented size occurred here,” said Markevitch.

Astronomers think the observed explosion may have occurred due to a spike in supply of ambient gas to the black hole, perhaps occurring when a galaxy fell into the center of the cluster.

The amount of energy required to create the cavity in Ophiuchus is about five times greater than the previous record holder, an event in a galaxy cluster called MS 0735.6+7421, and hundreds and thousands of times greater than typical clusters.

You can view a simulation of this violent event, in the constellation Ophiuchus, here:

No comments: